Question

A capillary tube of radius R is immersed in water and water rises in it to a height H. Mass of water in the capillary tube is M. If the radius of the tube is doubled, mass of water that will rise in the capillary tube will now be

• A. M
• B. 2M
• C. M/2
• D. 4M

Answer 1

Answer: (B)

2M

Answer 2

Mass of the liquid in capillary tube M = Vρ = (πr²h)ρ $\therefore M \propto r^{2}h \propto r$ [As $h \propto \frac{1}{r}$]

So if radius of the tube is doubled, mass of water will becomes 2M, which will rise in capillary tube.